A MIDI keyboard is a controller that sends what you play on its keys to a DAW or instrument as MIDI. Most produce no sound of their own; they play a software instrument at the other end. They range from compact models that connect to a computer over USB to models with faders and pads.
What it sends is performance information
Pressing a key sends MIDI information such as pitch, velocity, and how long you held it. Sound is produced when you choose a synthesizer or sampler in the DAW. Because you can change the instrument while keeping the same performance data, you can try out sounds after recording.
Connecting to a computer
Over USB, many devices are recognized without a driver. Check that the device is enabled in your DAW’s MIDI input settings and that the track you are playing is record-enabled. If you get no sound, check the input, the instrument, and the output in that order.
How to think about key count
A compact 25-key model is easy to fit on a desk, while 49 or 61 keys and up are handy for chords and two-handed playing. Even with fewer keys, octave switching lets you reach a wide range. Choose based on portability, desk space, and how you play.
Velocity and controls
Velocity support, which sends how hard you strike a key, is the basis of adding expression. Knobs, faders, pads, and pitch bend can be assigned to parameters in your instrument or DAW. To begin with, keyboard input alone is plenty.
Watch out for latency
If the sound arrives late after you play, the cause is often the buffer size in your audio settings rather than the MIDI keyboard. The basics of the production environment are covered in the DAW article.
